If that were true then the people in this thread arguing for the DNC to move to the left would be agreeing with the DNC themselves saying they need to move to the center. But the DNC is disagreeing about moving to the left. Clearly they think they are further left of center than they want to be, e.g. their goals are to move to the right. This is the exact opposite of what you are saying will work. Yes, the Overton window has shifted, but the DNC wants to keep shifting it towards the right, and not have it shift back leftwards at all.
When they lay on their belly with their legs all splayed out.